1) Field of the Invention
The present invention relates to an adjustable shoulder anchorage which allows to adjust the height of a shoulder webbing of a seat belt system to be mounted on an automotive vehicle or the like.
2) Description of the Related Art
Seat belt systems for automotive vehicles include those equipped with an adjustable shoulder anchorage mechanism for holding a slide anchor carrying a joint, on which a webbing is supported, in such a way that the vertical position of the slide anchor can be adjusted to permit proper application of the webbing to the shoulder of an occupant in accordance with the sitting height and physical constitution of the occupant.
One example of such adjustable shoulder anchorages will be described with reference to FIGS. 1 and 2, which also illustrate a first embodiment of the present invention.
A base 2 is mounted on a vehicle body 1 by a bolt 9. A slide anchor 3 carrying a slip joint 4 through which a webbing 11 extends is guided by the base 2 movably in the vertical direction as viewed in FIG. 2. The webbing 11 is therefore supported by the slip joint 4. The slide anchor 3 is provided with a lock pin 5, which is selectively allowed to engage a desired one of plural engagement holes 8 bored through the base 2 so that the slide anchor 3 is locked on the base 2.
The lock pin 5 is urged by a spring 6 toward the vehicle body, whereby its engagement with the desired one of engagement holes 8 is maintained. The anchor 3 can be unlocked from the base 2 by pulling out the lock pin 5 with a knob 7 attached to the lock pin 5 on a side opposite to the vehicle body 1.
FIGS. 1 and 2 also illustrate a cover 10, nut 12 and bolt 13 for mounting the slip joint 4 o the slide anchor 3, and a pin guide 14 fixed on the slide anchor 3 to guide the lock pin 5.
When it is desired to change the height of the slip joint 4 with the webbing 11 extending therethrough and supported thereby, it is only necessary to pull the knob 7 in an inboard direction until the lock pin 5 is pulled out of the engagement hole 8, to move the slide anchor 3 upwardly or downwardly along the base 2, and then to release the knob 7 at a position corresponding to the engagement hole 8 at an optimal height so that the lock pin 5 can be inserted in and held by the engagement hole 8 owing to the force of the spring 6.
To move the slide anchor 3 to the lowest height, a stopper 20 is generally employed to prevent the slide anchor 3 from moving down beyond a certain distance. The stopper 20 is formed by lancing and bending up a portion of the base or by using a separate member. A resin-made slide shoe 15 fixed on an end portion of the slide anchor 3 in order to permit smooth movement of the slide anchor 3 is brought into abutment against the stopper 20, whereby any further downward movement of the slide anchor 3 is prevented.
As has been described above, a slide shoe fixed on an end portion of a slide anchor is designed to abut against a stopper portion of a base so that the stopper portion and the slide anchor, both made of a metal, are prevented from abutment.
In a construction such that a slide shoe is simply fixed on a slide anchor as described above, it is impossible to sufficiently absorb an impact by the slide anchor at the lowest position thereof so that an impact noise is produced.